@Mullian Can you check the firmware version of the extra unit that you just bought? If you go to the Deco map > that unit, underneath of that page you'll see fw version. My assumption is that unit's fw is on the lowest version without Connection preference feature.

  @Espress0-0 

At your request, I have checked both nodes firmware version.  They are different than the three that I bought as a set.  Also, upon inspection of the bottom of the two new nodes, I see that they are Model: Deco XE75 Pro and their frimware veirson is the same 1.0.0. Buld 20221209 Rel. 78107. My origional models are XE75 firmware versions are the same 1.2.1. Build 20230601 Rel. 58453.

  @Mullian Alright then try upgrading your XE75 pro units' firmware in Deco app. That should fix :)

  @Espress0-0 After seeing the difference, I checked for updates and see that the Pro's have a frimware update available, 1.2.2 Build 20230601 Rel.66771.  I just updated the firmware on both Pro's.  Neither have any clients for now, the other three nodes have the missing option for Connection Preference.  It seems that a firmware update was needed and has resolved the problem.  Unless the problem remains for the Pros, I'll report back, otherwise, thanks for your direction.